INTRAMOLECULAR PHOTOADDITION REACTIONS OF (AMINOALKYL)STYRYLAMIDES

The photochemical reactions of a family of styrene-spacer-amine molecu les in which the spacer consists of a rigid amide group in the middle of a flexible alkane chain have been investigated. Our study of the ph otophysics of these molecules has shown that the amide linker can faci litate intramolecular styrene-amine exciplex formation (J. Phys. Chem. , in press). We report here the photochemical behavior of these amide- linked (aminoalkyl) styrylamides. Several tertiary amines are found to undergo regioselective alpha-C-H addition to the styrene double bond resulting in the formation of medium-ring iactams. A secondary amine u ndergoes N-H addition yielding an azalactam. The dependence of these r eactions upon spacer structure, amine and amide substitution, and solv ent polarity is discussed. (C) 1998 Elsevier Science S.A.